Decoding the annealing and defect effects in acceptor doped PbZrO₃ films with superior energy storage performance

Acceptor doped Pb_(1-x/2)K_xZrO₃ thin films were fabricated on Pt (111) /TiO₂/SiO₂/Si substrates via the chemical solution deposition method. Aliovalent potassium (K) was deliberately introduced to enhance the formation of oxygen vacancies and promote defect complexation, resulting in anomalous behavior -where E_AF initially increased before gradually decreasing, thus deviating from the tolerance factor rule due to the defect complexes. Furthermore, oxygen annealing effectively suppressed the oxygen vacancy defects induced during doping. The reduction of defects can make the electrical properties of the K-PZO-x films conform to the tolerance factor principle. Meanwhile, the defect engineering approach leads to a remarkable enhancement in the dielectric breakdown strength (from 1.4 MV/cm to 3.4 MV/cm for K-PZO-0.05). Notably, oxygen-annealed K-PZO-0.1 film demonstrates superior energy storage performance (53.3 J/cm³, at 3.2 MV/cm). This work demonstrates a viable defect-engineering strategy for significantly enhancing the energy storage performance of PZO-based antiferroelectric materials.